Causes

How the heart works

The heart is divided into four hollow chambers, two on the right and two on the left. To pump blood throughout the body, the heart uses its left and right sides for different tasks.

The right side of the heart moves blood to the lungs through vessels called pulmonary arteries. In the lungs, blood picks up oxygen then returns to the heart's left side through the pulmonary veins. The left side of the heart then pumps the blood through the aorta and out to the rest of the body.

How heart defects develop

During the first six weeks of pregnancy, the heart begins taking shape and starts beating. The major blood vessels that run to and from the heart also begin to form during this critical time during gestation.

It's at this point in your baby's development that heart defects may begin to develop. Researchers aren't sure exactly what causes most of these defects, but they think genetics, certain medical conditions, some medications and environmental factors, such as smoking, may play a role.

Types of heart defects

There are many different types of congenital heart defects, falling mainly into these categories:

• Holes in the heart. Holes can form in the walls between heart chambers or between major blood vessels leaving the heart.

  In certain situations, these holes allow oxygen-poor blood to mix with oxygen-rich blood, resulting in less oxygen being carried to your child's body. Depending on the size of the hole, this lack of sufficient oxygen can cause your child's skin or fingernails to appear blue or possibly lead to congestive heart failure.

  A ventricular septal defect is a hole in the wall between the right and left chambers on the lower half of the heart (ventricles). An atrial septal defect occurs when there's a hole between the upper heart chambers (atria).

  Patent ductus arteriosus (PAY-tunt DUK-tus ahr-teer-e-O-sus) is a connection between the pulmonary artery (containing deoxygenated blood) and the aorta (containing oxygenated blood). A complete atrioventricular canal defect is a condition that causes a hole in the center of the heart.

• Obstructed blood flow. When blood vessels or heart valves are narrow because of a heart defect, the heart must work harder to pump blood through them. Eventually, this leads to enlarging of the heart and thickening of the heart muscle. Examples of this type of defect are pulmonary stenosis or aortic stenosis (stuh-NO-sis).

• Abnormal blood vessels. Several congenital heart defects happen when blood vessels going to and from the heart don't form correctly, or they're not positioned the way they're supposed to be.

  A defect called transposition of the great arteries occurs when the pulmonary artery and the aorta are on the wrong sides of the heart.

  A condition called coarctation of the aorta happens when the main blood vessel supplying blood to the body is too narrow. Total anomalous pulmonary venous connection is a defect that occurs when blood vessels from the lungs attach to wrong area of the heart.

• Heart valve abnormalities. If the heart valves can't open and close correctly, blood can't flow smoothly.

  One example of this type of defect is called Ebstein's anomaly. In Ebstein's anomaly, the tricuspid valve — which is located between the right atrium and the right ventricle — is malformed and often leaks.

  Another example is pulmonary atresia, in which the pulmonary valve is missing, causing abnormal blood flow to the lungs.

• An underdeveloped heart. Sometimes, a major portion of the heart fails to develop properly. For example, in hypoplastic left heart syndrome, the left side of the heart hasn't developed enough to effectively pump enough blood to the body.
• A combination of defects. Some infants are born with several heart defects. Tetralogy of Fallot (teh-TRAL-uh-jee of fuh-LOW) is a combination of four defects: a hole in the wall between the heart's ventricles, a narrowed passage between the right ventricle and pulmonary artery, a shift in the connection of the aorta to the heart, and thickened muscle in the right ventricle.

Risk factors

Most congenital heart defects result from problems early in your child's heart development, the cause of which is unknown. However, certain environmental and genetic risk factors may play a role. They include:

• Rubella (German measles). Having rubella during pregnancy can cause problems in your baby's heart development. Your doctor can test you for immunity to this viral disease before pregnancy and vaccinate you against it if you aren't immune.
• Diabetes. You can reduce the risk of congenital heart defects by carefully controlling your diabetes before attempting to conceive and during pregnancy. Gestational diabetes generally doesn't increase your baby's risk of developing a heart defect.

• Medications. Certain medications taken during pregnancy may cause birth defects, including congenital heart defects. Give your doctor a complete list of medications you take before attempting to become pregnant.

  Medications known to increase the risk of congenital heart defects include thalidomide (Thalomid), angiotensin-converting enzyme (ACE) inhibitors, statins, the acne medication isotretinoin (Absorica, Amnesteem, Claravis) and lithium.

• Drinking alcohol during pregnancy. Avoid alcohol during pregnancy because it increases the risk of congenital heart defects.
• Smoking. Smoking during pregnancy increases the likelihood of a congenital heart defect in the baby.

• Heredity. Congenital heart defects sometimes run in families and may be associated with a genetic syndrome. Many children with Down syndrome — which is caused by an extra 21st chromosome (trisomy 21) — have heart defects. A missing piece (deletion) of genetic material on chromosome 22 also causes heart defects.

  Genetic testing can detect such disorders during fetal development. If you already have a child with a congenital heart defect, a genetic counselor can estimate the odds that your next child will have one.

Complications

Some potential complications that can occur with a congenital heart defect include:

• Congestive heart failure. This serious complication may develop in babies who have a significant heart defect. Signs of congestive heart failure include rapid breathing, often with gasping breaths, and poor weight gain.
• Slower growth and development. Children with more-serious congenital heart defects often develop and grow more slowly than do children who don't have heart defects. They may be smaller than other children of the same age and, if the nervous system has been affected, may learn to walk and talk later than other children.
• Heart rhythm problems. Heart rhythm problems (arrhythmias) can be caused by a congenital heart defect or from scarring that forms after surgery to correct a congenital heart defect.
• Cyanosis. If your child's heart defect causes oxygen-poor blood to mix with oxygen-rich blood in his or her heart, your child may develop a grayish-blue skin color, a condition called cyanosis.
• Stroke. Although uncommon, some children with congenital heart defects are at increased risk of stroke due to blood clots traveling through a hole in the heart and on to the brain.
• Emotional issues. Some children with congenital heart defects may feel insecure or develop emotional problems because of their size, activity restrictions or learning difficulties. Talk to your child's doctor if you're concerned about your child's moods.
• A need for lifelong follow-up. Children who have heart defects should be mindful of their heart problems their entire lives, as their defect could lead to an increased risk of heart tissue infection (endocarditis), heart failure or heart valve problems. Most children with congenital heart defects will need to be seen regularly by a cardiologist throughout life.

Prevention

Because the exact cause of most congenital heart defects is unknown, it may not be possible to prevent these conditions. However, there are some things you can do that might reduce your child's overall risk of birth defects and possibly heart defects, too, such as:

• Get a rubella (German measles) vaccine. A rubella infection during pregnancy may affect your baby's heart development. Be sure to get vaccinated before you try to conceive.
• Control chronic medical conditions. If you have diabetes, keeping your blood sugar in check can reduce the risk of heart defects. If you have other chronic conditions, such as epilepsy, that require the use of medications, discuss the risks and benefits of these drugs with your doctor.
• Avoid harmful substances. During pregnancy, leave painting and cleaning with strong-smelling products to someone else. Also, don't take any drugs, herbs or dietary supplements without consulting your doctor first. Don't smoke or drink alcohol during pregnancy.
• Take a multivitamin with folic acid. Daily consumption of 400 micrograms of folic acid has been shown to reduce birth defects in the brain and spinal cord and may help reduce the risk of heart defects as well.

Coping and support

It's natural for many parents to feel worried about their child's health, even after treatment of a congenital heart defect. Although many children who have congenital heart defects can do the same things children without heart defects can, here are a few things to keep in mind if your child has had a congenital heart defect:

• Developmental difficulties. Because some children who have congenital heart defects may have had a long recovery time from surgeries or procedures, their development may lag behind that of other children their age. Some children's difficulties may last into their school years, and they may have difficulties learning to read or write, as well.
• Emotional difficulties. Many children who have developmental difficulties may feel insecure about their abilities and may have emotional difficulties as they reach school age.
• Support groups. Having a child with a serious medical problem isn't easy and, depending on the severity of the defect, may be very difficult and frightening. You may find that talking with other parents who've been through the same situation brings you comfort and encouragement.

Talk with your child's doctor about ways to help you or your child with difficulties related to your child's heart condition. He or she can suggest resources, such as support groups or therapists that may be helpful to you or your child.

Preparing for an appointment

If your child has a life-threatening heart defect, it will likely be detected soon after birth, or possibly before birth as a part of routine exams during pregnancy.

If you suspect your child has a heart defect later in infancy or childhood, talk to your child's doctor. Be prepared to describe your child's symptoms and provide a family medical history, since some heart defects tend to be hereditary.

Your child's doctor may also want to know if the mother of the child had any medical conditions or used any medications or alcohol while pregnant that may have been a risk factor for developing a congenital heart defect.

What you can do

• Write down any signs and symptoms your child is experiencing, including any that may seem unrelated to heart problems. Write down when each symptom began.
• Make a list of all medications, vitamins or supplements that the mother of the child has been taking.
• Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions may help you make the most of your time together. You might want to ask the following questions:

• Are these signs and symptoms related to my family history?
• What kinds of tests does my child need? Do these tests require any special preparation?
• Does my child need treatment? If so, when?
• What is the best treatment?
• Do you think my child will experience any long-term complications?
• How will we monitor for possible complications?
• If I have more children, what are the odds of this condition occurring in them?
• Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

• When did you first notice your child's symptoms?
• Can you describe your child's symptoms?
• When do these symptoms occur?
• Have the symptoms been continuous or occasional?
• Do the symptoms seem to be getting worse?
• Do you have any family history of congenital heart defects?
• Does anything seem to improve your child's symptoms?
• Has your child been growing and meeting developmental milestones as expected?

Overview

Total anomalous pulmonary venous return (TAPVR) is a rare heart defect that's present at birth (congenital heart defect). It is sometimes called total anomalous pulmonary venous connection (TAPVC).

In this heart defect, the lung blood vessels (pulmonary veins) are attached to the wrong place in the heart.

Normally, oxygen-rich blood goes from the lungs to the upper left heart chamber (left atrium) and then flows through the body. In TAPVR, an abnormal connection of veins sends blood through the upper right heart chamber (right atrium) instead, where it mixes with oxygen-poor blood. As a result, blood flowing to the body doesn't have enough oxygen.

The specific type of TAPVR depends on where the veins connect. Most children born with TAPVR have no family history of congenital heart disease.

Symptoms

A baby with TAPVR may have breathing difficulty and appear blue (cyanotic) because of the lack of oxygen in the blood that goes out to the body, or because blood flow through the pulmonary veins is reduced or blocked.

A doctor may notice signs and symptoms of TAPVR soon after birth. But some children don't have symptoms until later on.

Diagnosis

Your child's doctor will perform a physical exam and listen to your child's heart with a stethoscope to check for a heart murmur.

An echocardiogram is generally used to diagnose total anomalous pulmonary venous return. This test uses sound waves to create images of your child's heart in motion. An echocardiogram can show pulmonary veins, holes in the heart and the size of the heart chambers. It can also measure the rate of blood flow.

Other tests such as an electrocardiogram (ECG or EKG), a chest X-ray or computerized tomography (CT) scan may be done if more information is needed.

Treatment

Surgery is generally needed when a child is a baby. The timing of surgery depends on whether or not there's a blockage. To repair this congenital heart defect, surgeons connect the pulmonary veins to the left atrium and close the hole between the atria.

A person with total anomalous pulmonary venous return will need regular doctor's checkups with cardiologists trained in congenital heart disease to monitor for infection, blockages or heart rhythm problems.